(i) Field of the Invention
The present invention relates to a process for labelling thin sheet material, more specially banknotes, using label tapes in the case of which in each case a desired number of single sheets in a train are stacked and the stack is labelled with the label tape. The invention is furthermore in respect of an apparatus for effecting the process.
(ii) The Prior Art
More specially in connection with automatic banknote sorting systems, a number of forms of apparatus have been designed in the case of which those banknotes, which at the end of the sorting process are seen to be good for further use, are stacked again in small stacks and done up with a label tape.
For example in the British Pat. No. 1,305,394 there is an account of a stacking and label taping system.
The general teaching of this old system is that the banknotes taken from the transport system by a stacker drum are placed on a stacking table placed under the stacker drum and, once the desired number of banknotes has been stacked, the stack is moved on to a second label taping table on which, lastly, the label tape is placed on it.
In the first stage of each labelling operation, a label tape, after being cut to the necessary length, is positioned at the middle of the taping table and as soon as this table with the label tape is moved under the stacking table, the stack is pushed with the help of driving parts from the stacking table on to the taping or labelling table. As part of the further operation, the label tape is placed by gripping parts, located at the sides of the table and moving towards the stack at its two sides, around the two longsides of the stack. Then the label tape, having a coating of hot-sealing material, has its two ends joined one on top of the other by the sealing operation. The stack, complete with its label tape, then lastly goes to a position where it is moved on to an output transport system.
In addition to the great amount of space needed by it, the design of this earlier system has shortcomings because it is complex and, for this reason, not free of trouble on operation.
With respect to running troubles there is, more specially, the shortcoming in this respect that the stack has to be moved a number of times while still untaped. Because of this motion, in which respect the pushing down of the stack from the stacking table on to the taping table is to be noted as being more specially the cause of trouble--the banknotes are in all cases moved more or less out of line within the stack--so that putting a label tape round the stack in position is made hard or may even not be possible, particularly at high speeds of taping.
A further shortcoming is that the forming of a stack with the true, desired shape does not in all cases take place with the old apparatus. It is, however, more specially, the forming of a trued-up stack which is an important condition for producing stacks with lined-up edges and on which the label tape may be fixed tightly. Although different banknote stacks all having the same number of notes may be very different in height, dependent on the quality of the notes, in the old machine no measures are taken for overcoming unevenness of stack size. Banknotes in stacks of different, uncontrolled height are, for this reason, not able to be taped with label tapes, or if taping is possible, the quality does not come up to the desired level. Furthermore the position at which the label tape is seated, in the case of the old apparatus, is greatly dependent on the condition of the banknotes being processed. Furthermore use with label tapes in a form cut to size earlier is the cause of shortcomings, because, namely, a label tape separating unit is necessary, which is likely to have trouble on running, and a somewhat complex positioning operation is necessary for placing the separated label tapes on the taping table.